Azo-dyestuffs



general fastness properties.

Patented Sept. 28, 1954 UNITED STATES PATENT OFFICE Germany,

assignor to Farbwerke Hoechst Aktiengescllschaft vormals Meister Luciusund Briining, Frankfurt am Main Hochst, Germany, a company of Germany NoDrawing. Application October 10, 1951, Serial No. 250,799

Claims priority, application Germany October 18, 1950 4 Claims. (01.260-187) The present invention relates to new azo-dyestuffs. It is basedon the observation that 4-amino-2-hydroxybenzene 1 carboxylic acid andthe derivatives thereof corresponding to the general formula OOOH NHz

wherein X and Y have the meaning indicated above and R stands for theradical of an azocomponent capable of being combined with diazocompoundsto form azo-dyestuifs. If the radical R contains an amino-group capableof being diazotized, the monoazo-dyestuffs formed can be furtherdiazotized and coupled again with any azo-component.

Since the new dyestufis contain the salicylic acid grouping, they can beafter-treated on the fiber or in substance with compounds yieldingmetal, particularly with chromium salts. The metal complex compoundsthus formed considerably improve the fastness properties of thedyestufis. The orange to black dyeings produced by the after-treatmentare distinguished by good With particular advantage the new dyestuffscan also be applied to the fiber directly in the form of their chromiumcomplex compounds according to the so-called meta-chrome process.

The following examples serve to illustrate the invention, but they arenot intended to limit it thereto, the parts being by weight, unlessotherwise stated:

Example 1 153 parts of 4-amino-2-hydroxybenzene-1- carboxylic acid aredissolved in 40 parts of caustic soda and 500 parts of water. 69 partsof sodium nitrite are then added. The solution thus obtained is causedto run into a mixture of ice and 280 parts of hydrochloric acid of 24 B.The suspension of the diam-compound is then introduced into a solutionof parts of 1- hydroxybenzene-2-carboxylic acid in 40 parts of causticsoda and 1000 parts of water to which 250 parts of calcined sodiumcarbonate have been added. After stirring for several hours theformation of the dyestuff is finished. The dyestuif is salted out withsodium chloride and after filtering with suction and drying it isobtained in the form of a brown-yellow powder. It dyes wool yellow-brownshades which, when after-treated with potassium bichromate and sulfuricacid, turn into medium brown shades of good fastness properties. Thedyestufi corresponds to the following formula OH COOH Dyeings of thesame good properties are obtained by applying the dyestuff to the fiberdirectly as chromium complex compound from a bath containingammonium-sulfate and potassium chromate according to the meta-chromeprocess.

In the following table further dyestuffs are described in which theamino-salicylic acid is used as diazo-component and which may beobtained in a manner similar to that described in the preceding example.

. Shade of the after- Diazo-Oomponent Azo-Component chromed dyeing l.4-amino-2-hydroxy- 4 amino 2 hydroxy reddish brown.

benzene 1 car benzene-l-carboxylic boxylic acid. acid. 2.4-amino-2-hydroxyl hydroxy -naphtha violetish brown.

benzene-l-carlene-5-sulionic acid. boxylic acid. 3. 4-amino-2-hydroxy-2- hydroxy -naphtha reddish brown.

benzene- 1 -carlene-fi-sulfonic acid. boxylic acid. 4. 4-amino-6-methyl-Z-hydroxy-S-methylmedium brown.

2 hydroxyben benzene-l-carboxylic zenie-l-earboxylic acid. 9.01 5. 4amino 3 chloro 1 hydroxy naphtha brown-violet.

2-hydroxybenlene-4-su1fonic acid. zene-l-carboxylic acid. 6. 4-amino-3methyl- 2 hydroxy-naphtha medium brown.

6 chloro 2 -l1y lcne-7-sulfonic acid. droxy-benzene-lcarboxylic acid. 7.4 amino 3.6 di 1.3-dihydroxy-benyellowish brown.

methyl-z-hyzene. droxybenzene-lcarboxylic acid. 8. 4-amino-3. G-di-1-(4-sulfopheny1)- reddish yellow.

chloro-2-hydroxy- 3 methyl 5 pyraz benzene 1 car olone. boxylic acid.

Example 2 amino-naphthalene which isobtained as follows: r

143 parts of l-amino-naphthalene are dissolved at boiling temperature in200 parts by volume of a N-hydrochloric acid and 1000 parts of water andthe solution is poured on ice. After stirring for 4 hours 300 parts ofcrystallized sodium acetate are added to the mixture of thediazo-compound and the l-amino-naphthalene, stirring is continued forfurther 4 hours and the dyestuff" formed is filtered with suction.

It is dissolved in 40 parts of caustic soda and 3000 parts of water, thesolution is filtered and mixed with 69 parts of sodium nitrite. Thesolution thus obtained is caused to run at a temperature between 5 C.and C. into 280 .parts of hydrochloric acid of 24 B. The diazo-solutionobtained is then introduced into a solution of 345 parts of a.1-hydroxynaphthalenei-sulfonic acid of 71.4 per cent. strength in 40parts of caustic soda and 1000 parts of water, to which 530 parts ofcalcined sodium carbonate have been added. As soon as the couplingreaction is finished, the disazo-dyestuff formed is completely saltedout, filtered with suction and thoroughly washed with sodium chloridesolution. After drying it is obtainedin the form or a dark powder. Itdyes wool from an acid bath dull claret-red shades which, whenafter-treated with potassium bichromate and sulfuric acid, turn intoreddish navy-blue shades of good fastness properties, especially of agood fastness to washing.

Similar dyestuiis are obtained by using, instead of l-amino-naphthalene,for instance l-amino- 3-methylbenzene, l-aminonaphthalene-G- or -7-sulfonic acid, 1-amino-2,5-dimethylbenzene, lamino-2,5-dimethoxybenzene,l-amino-2,5-dieth oxybenzene or 3-amino-4-methoxy-1-methylbenzene, andinstead of l-hydroxynaphthalene-4-sulfonic acid, for instancel-hydroxynaphthalene-fisulfonic acid, 2-hydroxynaphthalene-6-sulfonicacid, l-hydroxynaphthalene-3,6-disulfonic acid,2-hydroxynaphthalene-3,6-disu1fonic acid, 2- or l-hydroxynaphthalene,l-phenyl-3-methyl-5-pyrazolone, 1,3-dihydroxybenzene and the like.

I claim:

1. The azo-dyestufis corresponding to the following general formulawherein R and R1 each represent a. member selected from the group whichconsists of radicals of the benzene, naphthalene and pyrazolone series,the azo groups standing in one of the positions ortho and para to eachother, X and Y each represent a member selected from the group whichconsists of hydrogen, methyl and chlorine, and-wherein the radicals Rand R1 contain at least onegroup which imparts water-solubility to saidazo-dyestufi.

2. The azo-dyestuffs corresponding to the following general formulawherein R and R1 each represent a member selected from the group whichconsists of radicals of the benzene, naphthalene and pyrazolone series,the azo groups standing in one of the positions ortho and para to eachother, which contain at least one group which imparts water-solubilityto said azo dyestuff.

3. The azo-dyestuff corresponding to the following formula dyeing woolfrom an. acid bath dull claret-red shades which when after-chromed turninto reddish navy-blue shades of good fastness properties, especiallygoodfastness to washing.

4. The azo-dyestulf corresponding to the following formula SOaH dyeingwoolirom an acid bath claret-red shades which when after-chromed turninto reddish navy-blue shades of good .fastness properties.

References- Cited in the file of this patent UNITED STATES PATENTSNumber Name Date 438,438 Lauch 'et al' Oct. 14, 1890 1,357,169 MettlerOct. 19, 1915 1,8 l8,650 Ostertag Mar. 8, 1932

3. THE AZO-DYESTUFF CORRESPONDING TO THE FOLLOWING FORMULA